import java.util.ArrayList;
import java.util.List;

public class Test {
    public static void func(String str1,String str2){
       List<Character> list = new ArrayList<>();
        for (int i = 0; i < str1.length(); i++) {
            char ch = str1.charAt(i);
            if (!str2.contains(ch + "")){
                list.add(ch);
            }
        }
        for (Character ch:list) {
            System.out.print(ch);
        }
    }
    public static void main(String[] args) {
        String str1 = "welcome to bit";
        String str2 = "come";
        func(str1,str2);
    }
}
